How do submarines operate?

As a state-of-the-art weapon, the construction and operation of submarines require stringent technical standards and discipline.

A German Navy U-boat. Photo: History

Although they were developed quite early, it wasn't until World War I that German U-boats proved their worth in combat, sinking numerous Allied ships.

By World War II, after Britain developed radar and sonar technology for submarines, the US Navy also improved these systems along with the German-made snorkels.This significantly increases the submarine's diving time, making them indispensable weapons for any military power.

However, to become "killers" in the depths of the ocean, submarines must be built through a rigorous process, with the strictest standards, according to Marinebio.

Dive and surface mechanism

Submarines can either surface or submerge depending on ballast tanks located between their inner and outer hulls.

To dive, a submarine must have a buoyancy force less than its gravitational force. At this point, valves on the ballast tanks are opened, allowing seawater to flood in and push out the air, helping the submarine descend. The depth of the dive is controlled by adjusting the ratio of seawater to air in the ballast tanks. When the submarine's weight equals the displacement of the water inside the ballast tanks, the submarine will be in equilibrium, neither surfacing nor sinking further.

To help the ship float, simply use compressed air to push seawater out of the ballast tanks, making the buoyancy of the water greater than gravity.

Ballast tanks filled with air help the ship float (left). The ballast tanks are opened to allow water in, helping the ship to submerge. Graphic: submarinesafaris

Design and control

Submarines are always cylindrical in shape, with a small bow and two hulls: an inner hull and an outer hull. The inner hull, also known as the load-bearing hull, protects the crew from the immense pressure of deep dives and helps the submarine avoid the freezing temperatures of seawater. The outer hull is the outer shell that encloses the submarine.

Technological advancements have revolutionized submarine observation and operation. A key breakthrough in the Virginia-class submarines was the use of Photonics masts, which eliminated conventional periscopes. Instead of using mirrors and lenses to observe the water surface, several high-resolution color cameras were integrated to transmit images to large screens in the command center via fiber optic cables.

Model of the Soviet Project 641B diesel-electric submarine compartment system. Photo: sfox.ru

Submarines use various types of propulsion, including diesel engines, electric motors (or a combination of diesel and electric), and nuclear-powered engines.

Electric motors allow submarines to travel underwater for longer periods of time.and does not emit toxic gases likeEngines can use steam or gasoline. Electric motors are relatively small, but their battery systems are very large, heavy, and bulky. When seawater enters these batteries, they release toxic gases due to chemical reactions, and they themselves contain harmful acids.

Submarines use diesel engines to generate steam that turns turbines to produce electricity, which is used for heating and lighting. However, diesel engines burn air and emit toxic gases, so they are often combined with electric motors on submarines.

Nuclear submarines use nuclear-powered engines, so they don't need an air supply and can remain submerged indefinitely, only surfacing when necessary for resupply.

Rescue capabilities

In addition to operating procedures, submarines also need to ensure other factors when submerged, including survival support within the submarine (air, temperature, clean water), power supply, and navigation.

When a ship encounters a problem, the crew will send out a distress signal or deploy a beacon to indicate the ship's location. Depending on the severity, the nuclear reactors may be shut down, leaving the ship to rely solely on batteries.

When an incident occurs, the crew faces major risks such as water ingress, oxygen deprivation, dangerously high levels of toxic gases, and a drop in temperature due to the failure of the ship's heating system batteries. At this point, rescue efforts on the surface must be carried out urgently, usually within 48 hours of the incident.

According to VNE